Electronic printed circuit boards (PCBs), such as those used in computers or other electronic systems, commonly have a board with electronic components mounted thereon. The electronic components can generate a considerable amount of heat due to electrical power consumption. The heat must be dissipated from the components and the board to ensure proper functioning of the components and to prevent damage to any part of the PCB and the overall electronic system.
A variety of techniques have been developed to dissipate the heat. For instance, one low-cost technique simply allows the source of the heat to transfer the heat by convection to ambient air. However, this technique has a relatively low effectiveness. To enhance the effectiveness of dissipation by convection, a fan is added to force the air to flow over the component. A heat sink or heat spreader may be attached to the component to further enhance heat dissipation by conducting the heat away from the heat source to a surface area (larger than that of the component) from which the heat may be dissipated to the air. For even greater heat dissipation enhancement, increasingly sophisticated techniques have been developed, including “liquid loop” concepts involving the use of cooling fluids in heat pipes, active refrigeration systems and cooling plates. Each such enhancement, however, is offset by an added cost. It has been necessary to accept the added cost for enhanced heat dissipation techniques, though, because a significant trend in the electronics industry has been to continually increase the processing power and power consumption of electronic components, leading to increasingly greater needs for heat dissipation. The liquid loop concepts, for instance, are generally reserved for situations having relatively high heat dissipation requirements, because additional devices are required to be installed in the overall system.
The liquid loop concepts involve the use of a pump (or compressor), a cooling plate and a heat sink connected together by pipes, tubes or lines through which the cooling fluid flows. The cooling plate is placed on a surface of the heat source (the electronic component) to allow the heat to transfer to the cooling plate and then to the cooling fluid. The cooling fluid then flows to the heat sink at a location remote from the electronic component, such as outside of a housing containing the overall system of which the electronic component is a part, where the heat can be dissipated to ambient air. The cooling fluid then flows to the pump at another location remote from the electronic component and from the heat sink, which forces the cooling fluid through the pipes. Alternatively, for a liquid loop concept employing a compressor for active refrigeration of the cooling fluid, the cooling fluid flows from the cooling plate (attached to the electronic component) to the compressor, where the cooling fluid is compressed before flowing to the heat sink, or to a heat exchanger.
Since the pump, the heat sink and the cooling plate must be connected together by the pipes, since the cooling plate must be attached to the electronic component, and since the heat sink and pump must be remotely mounted within the overall system, there is considerable manufacturing and assembly work that must be done involving the proper installation of each of these devices when assembling the overall system. Therefore, in addition to the cost of the devices, the liquid loop concepts include significant time and cost for the assembling.